Syed Zabiuddin Ansari, the Lashkar-e-Taiba operative and 26/11 Mumbai terror plot handler whose arrest was disclosed on Monday, was known by many pseudonyms — Abu Jindal/Jundal, Abu Hamza and so on; but every one of his avatars was merely a mask for his accursed mission to inflict grievous harm on India and unleash terror on a mega-scale.

At one point during his satellite phone conversation from a Karachi control room to the Lashkar terrorists who were wreaking havoc in Mumbai in November 2008, Ansari coaches the gunmen on the message they should convey when they are interviewed by the media.

The chilling message he wanted to convey to the Indian government, through his jihadi-indoctrinated flunkeys, is this: "Hukumat ye jaan le yeh trailer hai, asal film baaqi hai" (This is just a trailer; the real film remains to be played out.)

The arrest of Zabiuddin Ansari alias Abu Jundal is a big breakthrough in the 26/11 investigation. Reuters

The man who fled to Pakistan to escape the anti-terrorism net that was closing in on him was used by elements of the Pakistani ISI and military that masterminded the audacious November 2008 attacks in Mumbai.

For years, he operated out of Pakistan-backed terror training modules in Pakistan-occupied Kashmir and safehouses in Karachi. And particularly after the Gujarat riots of 2002, in which he believed Muslims were savagely targeted, he intensified recruitments for his perverse jihadi cause to visit "vengeance" upon India.

Indian investigators have long claimed that Ansari was involved in the planning of the Mumbai train blasts of 2006 and even an alleged plot to assassinate Gujarat Chief Minister Narendra Modi.

Ajmal Kasab, the long surviving gunman who participated in the November 2008 terror attacks, had also admitted during interrogation that he and the other LeT terrorists had been trained by a Karachi-based operative known as Abu Jundal, who even taught them Hindi to manage on the streets of Mumbai.

Having built up a dossier on him, India had long sought the extradition of Ansari alias Abu Jindal/Jundal/Hamza from Pakistan, but nothing came of it, given Pakistan's unwillingness to acknowledge that the terror plot was masterminded in Pakistan.

But strikingly, in February 2009, Pakistan's Interior Minister Rehman Malik claimed that the Pakistani police had arrested seven persons for involvement in the conspiracy to carry out the 26/11 terror acts. One of those arrested was an operative named Abu Hamza. Even given the fact that the LeT frequently uses the same handle for different operatives, Indian investigators had reason to believe that it was their man.

India's request to Pakistan for Ansari's extradition for trial was never acknowledged. And the case in Pakistan went nowhere, largely because the Pakistani ISI and the military didn't want their complicity in the 26/11 attacks exposed. But surprisingly, earlier this year, Ansari surfaced in Saudi Arabia, travelling on a Pakistani passport under another assumed name: Riasat Ali.

Indian investigators were evidently tracking his every move, and were working patiently behind the scenes. Last month, barely days ahead of the home secretary-level talks between India and Pakistan, Indian investigators removed Ansari's name from the list of suspects they had given Pakistan.

It was the surest sign that Ansari had shifted base, and was no longer in Pakistan. Whether he flew the coop isn't immediately clear: given the fact that Ansari was working in tandem with Pakistani intelligence and military services, the alternative proposition — that the Pakistani government had let him go — is harder to envisage.

In any case, Indian investigators and intelligence officials began patiently to work on Saudi officials with a request for Ansari's extradition to face trial on terror charges. Given Saudi Arabia's role in spreading intolerant Wahhabi hatred, which has played no small role in indoctrinating jihadi philosophy into hotheads in the Indian subcontinent, it appeared initially that the efforts to secure Saudi cooperation were doomed to fail.

But other pieces in the geostrategic puzzle were simultaneously falling into place.

Indicatively, the US administration has in recent months been keen to wean India off its need for oil from Iran (and abide by the sanctions regime against Iran) and to source it from Saudi Arabia. India has been dragging its feet on that. As part of its effort, the US has been nudging Saudi Arabia to extend cooperation to India in the area of counter-terrorism to "sweeten the deal".

Just last week, US Defence Secretary and former CIA chief Leon Panetta was in Saudi Arabia following the death of the Crown Prince, who had as Interior Minister led the kingdom's fight against terrorism.

It's possible that Panetta's visit catalysed and greased the tracks for Saudi Arabia's decision to "deliver" Ansari to India. (Looking back, it's entirely possible that Pakistan may have "released" Ansari and sent him on to Saudi Arabia under pressure from the US. If that's true, it's perhaps a sign that Pakistan is wilting under pressure — after all, Ansari can now reveal disquieting details of Pakistani ISI-military involvement in the 26/11 terror attacks.)

In other words, the diligent and painstaking work of Indian intelligence and security officials in working with US and Saudi officials has yielded their biggest catch of a terrorist handler associated with the 26/11 attacks.

It's a rare instance of success, one that bodes well for India's fight against jihadi terror. Straightaway, it gives India with yet more ammunition to turn the heat on Pakistan for its role in sponsoring terror in India, for which it has thus far refused to own up responsibility.